Coated article having a protective coating containing silicon nitride and/or silicon oxynitride

ABSTRACT

A coated article includes a substrate, a functional layer over at least a portion of the substrate, and a protective coating over at least a portion of the functional layer, wherein an uppermost layer of the functional layer is a metal oxide layer, and wherein the protective coating comprises a metal nitride layer and a metal oxynitride layer that is disposed between and in contact with at least part of the metal nitride layer and the metal oxide layer of the functional layer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/631,283, filed Feb. 15, 2018, U.S. Provisional PatentApplication No. 62/631,588, filed on Feb. 16, 2018, and U.S.

Provisional Patent Application No. 62/734,656, filed on Sep. 21, 2018,each of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

An invention according to the present disclosure relates generally tosolar control coatings having a top coat including a metal nitride layerand/or a metal oxynitride disposed over a metal oxide layer.

Technical Considerations

Coating stacks of coated articles may corrode over time. To protect fromthis, protective coatings can be applied to coating stacks. For example,titanium dioxide films disclosed in U.S. Pat. Nos. 4,716,086 and4,786,563 are protective films that provide chemical resistance to acoating. Silicon oxide disclosed in Canadian Patent Number 2,156,571,aluminum oxide and silicon nitride disclosed in U.S. Pat. Nos.5,425,861; 5,344,718; 5,376,455; 5,584,902 and 5,532,180; and in PCTInternational Patent Publication No. 95/29883 are also protective filmsthat provide chemical resistance to a coating. This technology could beadvanced by more chemically and/or mechanically durable coatings.

An additional known problem with coating stacks including protectivecoatings occurs in silver-based coating stacks. In certain coatedarticles, a top layer of a functional coating includes a metal oxidelayer, such as a layer of zinc oxide, is positioned over a terminalmetal-primer layer of the functional coating. This may cause corrosionor glitter defects in the stack upon extended exposure to acondensing-humidity environment. Thus, a further need exists to reduceor avoid these defects in a coating stack.

SUMMARY OF THE DISCLOSURE

According to one aspect of the invention, a coated article is provided.The coated article comprises a substrate, a first functional layer overat least a portion of the substrate, and a protective coating over atleast a portion of the functional layer, wherein an uppermost layer ofthe functional layer is a metal oxide film, and wherein the protectivecoating comprises one or more layers of a metal nitride, a metaloxynitride, or a combination thereof.

In one aspect, the coated article comprises: a glass substrate; a firstlayer of zinc stannate over at least a portion of the glass substrate; alayer of zinc oxide over at least a portion of the layer of zincstannate; a layer of silver over at least a portion of the layer of zincoxide; a primer layer comprising Ti, TiAl and/or oxides thereof over atleast a portion of the layer of silver; a second layer of zinc stannateover at least a portion of the primer layer; a metal oxynitride layercomprising silicon oxynitride directly over at least a portion of thesecond layer of zinc stannate; a metal nitride layer comprising silicondirectly over at least a portion of the metal oxynitride layer; and asecond protective layer comprising Ti, TiAl, and/or oxides of either ofthe preceding over at least a portion of the metal nitride layer.

In another aspect, a coated article is provided. The coated articlecomprises a substrate, a functional layer, having an uppermost layer,over at least a portion of the substrate, and a protective coating overat least a portion of the functional layer, wherein the uppermost layerof the functional layer is a dielectric layer having an index ofrefraction of at least 1.5, and not more than 2.1.

In another aspect, a coated article is provided comprising a substrate,a functional layer over at least a portion of the substrate, and aprotective coating over at least a portion of the functional layer,wherein the functional layer comprises at least one metallic layer and aprimer layer disposed at least partially over and in contact with atleast part of the at least one metallic layer, and wherein an uppermostlayer of the functional layer is disposed over and in contact with atleast part of the primer layer, and the uppermost layer of thefunctional layer does not include zinc oxide.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the following drawingfigures wherein like reference numbers identify like parts throughout.

FIG. 1A is a side view (not to scale) of an insulating glass unit(“IGU”) having a coating of the invention.

FIG. 1B is a sectional view of a transparency having a coating of theinvention.

FIGS. 2A and 2B are sectional views (not to scale) of coatings of theinvention.

FIG. 3 is a sectional view (not to scale) of a coating according to anexample of the invention.

FIGS. 4A and 4B are sectional views (not to scale) of a coatingaccording to an example of the invention.

FIG. 5 is a sectional view (not to scale) of a coating according to anexample of the invention.

FIG. 6 is a sectional view (not to scale) of a coating according to anexample of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As used herein, spatial or directional terms, such as “left”, “right”,“inner”, “outer”, “above”, “below”, and the like, relate to theinvention as it is shown in the drawing figures. However, it is to beunderstood that the invention can assume various alternativeorientations and, accordingly, such terms are not to be considered aslimiting. Further, as used herein, all numbers expressing dimensions,physical characteristics, processing parameters, quantities ofingredients, reaction conditions, and the like, used in thespecification and claims are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical values set forth in the following specificationand claims may vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical value should at least be construedin light of the number of reported significant digits and by applyingordinary rounding techniques. Moreover, all ranges disclosed herein areto be understood to encompass the beginning and ending range values andany and all subranges subsumed therein. For example, a stated range of“1 to 10” should be considered to include any and all subranges between(and inclusive of) the minimum value of 1 and the maximum value of 10;that is, all subranges beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5,5.5 to 10, and the like. “A” or “an” refers to one or more.

Further, as used herein, the terms “formed over”, “deposited over”, or“provided over” mean formed, deposited, or provided on but notnecessarily in contact with the surface. For example, a coating layer“formed over” a substrate does not preclude the presence of one or moreother coating layers or films of the same or different compositionlocated between the formed coating layer and the substrate.Additionally, all documents, such as, but not limited to, issued patentsand patent applications, referred to herein are to be considered to be“incorporated by reference” in their entirety. As used herein, the term“film” refers to a coating region of a desired or selected coatingcomposition. A “layer” can comprise one or more “films”, and a “coating”or “coating stack” can comprise one or more “layers”. The term“asymmetrical reflectivity” means that the visible light reflectance ofthe coating from one side is different than that of the coating from theopposite side. The term “critical thickness” means a thickness abovewhich a coating material forms a continuous, uninterrupted layer andbelow which the coating material forms discontinuous regions or islandsof the coating material rather than a continuous layer. The term“subcritical thickness” means a thickness below the critical thicknesssuch that the coating material forms isolated, non-connected regions ofthe coating material. The term “islanded” means that the coatingmaterial is not a continuous layer but, rather, that the material isdeposited to form isolated regions or islands.

For purposes of the following discussion, the coated articles describedherein may be discussed with reference to use with an architecturaltransparency, such as, but not limited to, an insulating glass unit(IGU). As used herein, the term “architectural transparency” refers toany transparency located on a building, such as, but not limited to,windows and sky lights. However, it is to be understood that the coatedarticles described herein are not limited to use with such architecturaltransparencies but could be practiced with transparencies in any desiredfield, such as, but not limited to, laminated or non-laminatedresidential and/or commercial windows, insulating glass units, and/ortransparencies for land, air, space, above water and underwatervehicles. In one aspect or embodiment, the coated articles as describedherein are transparencies for use in a vehicle, such as a window or asunroof. Therefore, it is to be understood that the specificallydisclosed exemplary aspects or embodiments are presented simply toexplain the general concepts of the invention, and that the invention isnot limited to these specific exemplary embodiments. Additionally, whilea typical “transparency” can have sufficient visible light transmissionsuch that materials can be viewed through the transparency, the“transparency” need not be transparent to visible light but may betranslucent or opaque. That is, by “transparent” is meant having visiblelight transmission of greater than 0% up to 100%.

A non-limiting transparency 10 incorporating features of the inventionis illustrated in FIG. 1A. The transparency 10 can have any desiredvisible light, infrared radiation, or ultraviolet radiation transmissionand/or reflection.

The exemplary transparency 10 of FIG. 1A is in the form of aconventional insulating glass unit and includes a first ply 12 with afirst major surface 14 (No. 1 surface) and an opposed second majorsurface 16 (No. 2 surface). In the illustrated non-limiting embodiment,the first major surface 14 faces the building exterior, i.e., is anouter major surface, and the second major surface 16 faces the interiorof the building. The transparency 10 also includes a second ply 18having an inner (first) major surface 20 (No. 3 surface) and an outer(second) major surface 22 (No. 4 surface) and spaced from the first ply12. This numbering of the ply surfaces is in keeping with conventionalpractice in the fenestration art. The first and second plies 12, 18 canbe connected in any suitable manner, such as by being adhesively bondedto a conventional spacer frame 24. A gap or chamber 26 is formed betweenthe two plies 12, 18. The chamber 26 can be filled with a selectedatmosphere, such as air, or a non-reactive gas such as argon or kryptongas. A solar control coating 30 (or any of the other coatings describedbelow) is formed over at least a portion of one of the plies 12, 18,such as, but not limited to, over at least a portion of the No. 2surface 16 or at least a portion of the No. 3 surface 20. Although, thecoating could also be on the No. 1 surface or the No. 4 surface, ifdesired. Examples of insulating glass units are found, for example, inU.S. Pat. Nos. 4,193,236; 4,464,874; 5,088,258; and 5,106,663.

The exemplary transparency of FIG. 1B is in the form of a conventionaltransparency 110 for a vehicle, such as a window or sunroof. Forclarity, seals, connectors, and opening mechanisms are not shown, nor isthe complete vehicle. The transparency includes a first ply 112 with afirst major surface 114 (No. 1 surface) and an opposed second majorsurface 116 (No. 2 surface) mounted in the body of a vehicle 118 (shownin part). In the illustrated non-limiting embodiment, the first majorsurface 114 faces the vehicle's exterior, and thus is an outer majorsurface, and the second major surface 116 faces the interior of thevehicle. Non-limiting examples of a vehicle body include: an automobileroof in the case of a sunroof, an automobile door or frame in the caseof an automobile window, or a fuselage of an airplane. The transparencymay be affixed to a mechanism by which the transparency, such as a carwindow or sunroof, can be opened and closes, as is broadly known in thevehicular arts. A solar control coating 130, or any of the othercoatings described herein, is shown as formed over the No. 1 surface114, it may be formed over at least a portion of the No. 2 surface 116.

In the broad practice of the invention, the plies 12, 18, 112 of thetransparency 10, 110 can be of the same or different materials. Theplies 12, 18, 112 can include any desired material having any desiredcharacteristics. For example, one or more of the plies 12, 18, 112 canbe transparent or translucent to visible light. By “transparent” ismeant having visible light transmission of greater than 0% up to 100%.Alternatively, one or more of the plies 12, 18, 112, can be translucent.By “translucent” is meant allowing electromagnetic energy (e.g., visiblelight) to pass through but diffusing this energy such that objects onthe side opposite the viewer are not clearly visible. Examples ofsuitable materials include, but are not limited to, plastic substrates(such as acrylic polymers, such as polyacrylates;polyalkylmethacrylates, such as polymethylmethacrylates,polyethylmethacrylates, polypropylmethacrylates, and the like;polyurethanes; polycarbonates; polyalkylterephthalates, such aspolyethyleneterephthalate (PET), polypropyleneterephthalates,polybutyleneterephthalates, and the like; polysiloxane-containingpolymers; or copolymers of any monomers for preparing these, or anymixtures thereof); ceramic substrates; glass substrates; or mixtures orcombinations of any of the above. For example, one or more of the plies12, 18, 112 can include conventional soda-lime-silicate glass,borosilicate glass, or leaded glass. The glass can be clear glass. By“clear glass” is meant non-tinted or non-colored glass. Alternatively,the glass can be tinted or otherwise colored glass. The glass can beannealed or heat-treated glass. As used herein, the term “heat treated”means tempered or at least partially tempered. The glass can be of anytype, such as conventional float glass, and can be of any compositionhaving any optical properties, e.g., any value of visible transmission,ultraviolet transmission, infrared transmission, and/or total solarenergy transmission. By “float glass” is meant glass formed by aconventional float process in which molten glass is deposited onto amolten metal bath and controllably cooled to form a float glass ribbon.Examples of float glass processes are disclosed in U.S. Pat. Nos.4,466,562 and 4,671,155.

The plies 12, 18, 112 can each comprise, for example, clear float glassor can be tinted or colored glass or one ply 12, 18 can be clear glassand the other ply 12, 18, colored glass. Although not limiting, examplesof glass suitable for the first ply 12 and/or second ply 18 aredescribed in U.S. Pat. Nos. 4,746,347; 4,792,536; 5,030,593; 5,030,594;5,240,886; 5,385,872; and 5,393,593. The plies 12, 18, 112 can be of anydesired dimensions, e.g., length, width, shape, or thickness. In oneexemplary automotive transparency, the first and second plies can eachbe 1 mm to 10 mm thick, such as 1 mm to 8 mm thick, such as 2 mm to 8mm, such as 3 mm to 7 mm, such as 5 mm to 7 mm, such as 6 mm thick.

In non-limiting embodiments of the coated articles described herein, thesolar control coating 30, 130 of the invention is deposited over atleast a portion of at least one major surface of one of the glass plies12, 18, 112. In the example according to FIG. 1A, the coating 30 isformed over at least a portion of the inner surface 16 of the outboardglass ply 12, 112; additionally or alternatively, it is to be understoodthat in non-limiting examples consistent with the present disclosure acoating may be formed over at least a portion of the inner surface 20 ofthe inboard glass ply 18. As used herein, the term “solar controlcoating” refers to a coating comprised of one or more layers or filmsthat affect the solar properties of the coated article, such as, but notlimited to, the amount of solar radiation, for example, visible,infrared, or ultraviolet radiation, reflected from, absorbed by, orpassing through the coated article; shading coefficient; emissivity,etc. The solar control coating 30 can block, absorb, or filter selectedportions of the solar spectrum, such as, but not limited to, the IR, UV,and/or visible spectrums.

The coatings described herein, such as the solar control coatings 30,130, can be deposited by any useful method, such as, but not limited to,conventional chemical vapor deposition (CVD) and/or physical vapordeposition (PVD) methods. Examples of CVD processes include spraypyrolysis. Examples of PVD processes include electron beam evaporationand vacuum sputtering (such as magnetron sputter vapor deposition(MSVD)). Other coating methods could also be used, such as, but notlimited to, sol-gel deposition. In one non-limiting embodiment, thecoating 30, 130 is deposited by MSVD. Examples of MSVD coating devicesand methods will be well understood by one of ordinary skill in the artand are described, for example, in U.S. Pat. Nos. 4,379,040; 4,861,669;4,898,789; 4,898,790; 4,900,633; 4,920,006; 4,938,857; 5,328,768; and5,492,750.

FIG. 2 shows schematically an example of a coated article 200 accordingto the present disclosure. The coated article comprises a substrate 210.Substrate 210 may include any desired properties, and be of any desiredthickness. The substrate 210 may comprise any suitable transparentmaterial or materials, such as, for example and without limitation, thepolymers, glass, and/or ceramic substrates described above in thecontext of plies 12, 18, and 112. In non-limiting examples, substrate210 may comprise a glass substrates as described above in reference toplies 12, 18, 112, as shown in FIG. 1A or 1B. However, it is to beunderstood that the present invention may be applied to other substratesas well, such as those used in solar cells.

Functional layer 220 is disposed over at least a portion of substrate210. As used in FIGS. 2-6, functional layer 220, 320, 420, 520 can beany functional coating. For example, it can include one or moredielectric films and/or one or more metal films. Alternatively, thefunctional layer 220, 320, 420, 520 may include a transparent conductiveoxide (TCO), for example and without limitation, as disclosed in U.S.patent application Ser. No. 15/669,414. The functional layer 220, 320,420, 520 can include the stack as described in any of U.S. PatentApplication Publication Nos. 2017/0341977, 2014/0272453, 2011/0236715,and/or U.S. patent application Ser. No. 15/669,414, or any portionthereof. These exemplary stacks of the functional layer, except asspecifically discussed below, are schematically represented at element330, 430, 530 of FIGS. 3-6, with details of aspects of stacks 330 and530 being depicted in, and described in reference to, FIGS. 3 and 6,respectively.

The functional layer may include one or more metallic layers. One ormore metallic films within the functional layer 220, 320, 420, 520 maybe comprised of silver, gold, palladium, copper, aluminum, and/or amixture, and/or an alloy of any of the preceding. Any metallic layer inthe functional layer 220, 320, 420, 520 may be continuous ordiscontinuous.

The one or more metallic layers can be a continuous layer. Continuousmetallic layers have a thickness in the range of 50 Å to 200 Å,preferably 55 Å to 150 Å, more preferably 55 Å to 100 Å, most preferably60 to 80 Å.

FIGS. 3, 4A, and 4B depict examples wherein the uppermost layer of thefunctional layer 320 comprises a dielectric layer, referred to asuppermost dielectric layer 322 as the uppermost film in the functionlayer 320. Examples of the uppermost dielectric layer 322 of thefunctional layer 320 can have a thickness in the range of 50 Å to 750 Å,preferably 250 Å to 600 Å, more preferably such as 300 Å to 550 Å, andmost preferably 330 Å to 500 Å.

As shown in FIG. 4B, the uppermost dielectric layer 322 may include afirst film 324 shown over the optional primer layer 328, and a secondfilm 326 over the first film and in contact with a protective coating350. The first film 324 and the second film 326 of the uppermostdielectric layer 322 can be a metal oxide, metal nitride or metaloxynitride film. The metal of the first film 324 and the second film 326can be titanium, hafnium, zirconium, niobium, zinc, bismuth, lead,indium, tin, aluminum, silicon and mixtures thereof.

In one non-limiting embodiment, the first film 324 of the uppermostdielectric layer 322 can be a zinc/tin alloy oxide. By “zinc/tin alloyoxide” is meant both true alloys, and mixtures of the oxides. Zinc oxidecan be deposited from a zinc cathode that includes other materials toimprove the sputtering characteristics of the cathode. As such, thezinc/tin alloy oxide can be obtained from magnetron sputtering vacuumdeposition from a cathode of zinc and tin. For example, the zinc cathodecan include a small amount (e.g., up to 20 wt. %, up to 15 wt. %, up to10 wt. %, or up to 5 wt. %) of tin to improve sputtering. In which case,the resultant zinc oxide film would include a small percentage of tinoxide, e.g., up to 10 wt. % tin oxide, e.g., up to 5 wt. % tin oxide. Acoating layer deposited from a zinc cathode having up to 10 wt. % tin(added to enhance the conductivity of the cathode) is referred to hereinas “a zinc oxide film” even though a small amount of tin may be present.One non-limiting cathode can comprise zinc and tin in proportions offrom 5 wt. % to 95 wt. % zinc and from 95 wt. % to 5 wt. % tin, such asfrom 10 wt. % to 90 wt. % zinc and from 90 wt. % to 10 wt. % tin.However, other ratios of zinc to tin could also be used.

One suitable metal alloy oxide that can be present in the first film 324or the second film 226 is zinc stannate. By “zinc stannate” is meant acomposition of Zn_(X)Sn_(1-X)O_(2-X) (Formula 1) where “x” varies in therange of greater than 0 to less than 1. For instance, “x” can be greaterthan 0 and can be any fraction or decimal between greater than 0 to lessthan 1. For example, where x=2/3, Formula 1 is Zn_(2/3)Sn_(1/3)O_(4/3),which is more commonly described as “Zn₂SnO₄”. A zincstannate-containing film has one or more of the forms of Formula 1 in apredominant amount in the layer.

FIG. 4A discloses one embodiment of the coated article and comprises asubstrate 310, a functional layer 320 according to any aspect orembodiment described herein, and a protective coating 350, comprising ametal nitride film 356 over the functional layer 320, and a secondprotective film 360 over the metal nitride film 356. The functionallayer comprises an uppermost dielectric layer, e.g., as shown in FIGS. 3and 4B. In one non-limiting embodiment, the uppermost dielectric layer322 may consist of a metal oxide, such as zinc stannate. In a furthernon-limiting embodiment, the uppermost dielectric layer 322 may have anindex of refraction of not less than 1.5, and not more than 2.1. In afurther non-limiting embodiment, the uppermost dielectric layer 322 mayhave an index of refraction of not less than 1.7, and not more than 1.9,and still more preferably not less than 1.8, and not more than 1.85.

As shown in FIG. 4B, in another non-limiting example comprising asubstrate 310, and a functional layer 320 comprising an uppermostdielectric layer 322, an optional primer layer 328, and a stack 330, forexample a stack as described in reference to FIG. 3, the uppermostdielectric layer 322 of the functional layer 320 may include a firstfilm 324, comprised of, or consisting of, a metal oxide, such as zincoxide, which is deposited over at least a portion of the optional primerlayer 328. A second film 326 of the uppermost dielectric layer 322 ofthe functional layer 320, which is positioned over at least a portion ofthe first film 324, may comprise zinc stannate.

As shown in FIGS. 3-4B, the functional layer 320 also may include anoptional primer layer 328 disposed under the dielectric layer 322. Theoptional primer layer 328 can be a single film or a multiple film layer.The optional primer layer 328 can include an oxygen-capturing materialthat can be sacrificial during the deposition process to preventdegradation or oxidation of the metallic layer 334 during the sputteringprocess or subsequent heating processes. The optional primer layer 328can also absorb at least a portion of electromagnetic radiation, such asvisible light, passing through the coating 300. Examples of materialsuseful for the optional primer layer 328 include titanium, silicon,silicon dioxide, silicon nitride, silicon oxynitride, nickel-chromealloys (such as Inconel), zirconium, aluminum, alloys of silicon andaluminum, alloys containing cobalt and chromium (e.g., Stellite®), andmixtures of any of the preceding. In a non-limiting embodiment, theoptional primer layer 328 may comprise titanium, or titanium andaluminum, which are deposited as a metal and at least a portion of thetitanium, or titanium and aluminum are subsequently oxidized. Theoptional primer layer 328 can have a thickness in the range of from 5 Åto 50 Å, e.g., from 10 Å to 35 Å, e.g., from 15 Å to 35 Å, e.g. from 10Å to 20 Å, e.g. from 10 Å to 30 Å, e.g., from 20 Å to 30 Å, e.g. from 30Å to 40 Å. In another example, the optional primer layer 328 can have athickness in the range of from 5 Å to 50 Å, e.g., from 10 Å to 25 Å,e.g., from 15 Å to 25 Å, e.g., from 15 Å to 22 Å; e.g. from 25 Å to 36Å. As shown, the optional primer layer 328, when present, is disposedunder and in direct contact with the first film 324 of the dielectriclayer 322. While it is shown in the figures, it is to be understood thatexamples according to the invention do not necessarily include theoptional primer layer 328.

With reference to FIG. 2A, protective coating 250 is disposed over atleast a portion of the functional layer 220 and is the uppermost layerof the coated article. Protective coating 250 can help protect theunderlying coating layers, such as functional layer 220 and any of itscomponent films and layers, from mechanical and/or chemical attack. FIG.2B is similar in structure to the coated article depicted in FIG. 2A,showing a substrate 210 and a protective coating 250, but includes afirst functional layer 220 that is the same as the functional layer 220of FIG. 2A, and a second functional layer 220′ disposed under the firstfunctional layer 220 and over the substrate 210. The first functionallayer 220 may be the same as, or different from the second functionallayer 220′. For example, and without limitation, the first functionallayer 220 comprises a dielectric layer, a metallic layer over thedielectric layer, and optionally, a primer layer over the metalliclayer, and the uppermost dielectric layer comprises a metal oxide filmover the metallic layer, and over the primer layer when the primer layeris present. The second functional layer 220′ comprises a seconddielectric layer over the substrate 210, a second metallic layer overthe second dielectric layer, and optionally a second primer layer overthe second metallic layer. In one example, one of the first and/orsecond metallic layer is subcritical. In another example neither issubcritical. In yet another example, the coated article comprises athird functional layer (not shown) that is under the second functionallayer 220′ and over the substrate 210, and which is the same as ordifferent from any of the first or second functional layers 220, 220′.It is noted that multiple smaller functional layers may be layered toproduce a larger functional layer that may or may not have propertiesthat are unique to any particular combination of smaller functionallayers, such as with single-silver, double-silver, and triple-silvercoatings, optionally comprising one or more subcritical silver layers.

In one embodiment of the invention, referring to FIG. 4A, the protectivelayer 350 may comprise silicon oxide, silicon oxynitrides, siliconnitride, a mixture of any two of more of the preceding, and/or an alloyof any of the preceding, and which may provide increased durability tothe functional layer 320. The protective layer 350 may include ofsilicon oxide, silicon oxynitrides, and/or silicon nitride depositedwith other materials having superior electrical conductivity to improvesputtering of the silicon. For example, during deposition, the siliconcathode can include a small amount (e.g., up to 20 wt. %, up to 15 wt.%, up to 10 wt. %, or up to 5 wt. %) of aluminum to improve sputtering.In which case, the resultant protective layer would include a similarpercentage of aluminum, e.g., up to 15 wt. % aluminum, e.g., up to 10wt. % aluminum, e.g., up to 5 wt. % aluminum. A coating layer depositedfrom a silicon cathode having up to 10 wt. % aluminum added to enhancethe conductivity of the cathode is referred to herein as “a siliconoxide”, “a silicon oxynitride”, or “a silicon nitride” layer or film,even though a small amount of aluminum may be present. The small amountof aluminum in the cathode (e.g., less than or equal to 15 wt. %, suchas less than or equal to 10 wt. %, such as less than or equal to 5 wt.%) is believed to form aluminum nitride in the predominantly siliconnitride protective layer 350. In the case of a silicon nitride layer,the protective layer 350 may be formed in a nitrogen atmosphere;however, it is to be understood that other gasses, such as oxygen, maybe present in the atmosphere during the deposition of the protectivelayer 350.

In another embodiment, referring to FIG. 4B, the protective coating 350may be comprised of a film of a metal nitride 356, such silicon nitride,disposed over and in contact with a film of metal oxynitride 354, suchas SiON, disposed over or and in contact with the uppermost dielectriclayer 322 of the functional layer 320. Examples of metal oxynitride film354 also, or alternatively, may include two or more metal nitridesand/or alloys of one or more metal nitrides. Examples of metal nitridefilm 356 also, or alternatively, may include mixtures of two or moremetal oxynitrides and/or alloys of one or more metal oxynitride. Theprotective coating 350 may provide increased durability to thefunctional layer 320. The protective coating 350 may be deposited withother materials having superior electrical conductivity to improvesputtering of the metal.

The protective coating 250, 350 has a total thickness (i.e. the sum ofall of the thickness of the layers or films within the protectivecoating 250, 350) in the range of 320 Å to 800 Å, 420 Å to 800 Å, 400 Åto 700 Å, 500 Å to 800 Å, 600 Å to 700 Å, 580 Å to 630 Å or 620 Å to 670Å.

The atomic ratio of oxygen and nitrogen in metal oxynitrides can vary,from 0 wt. % to 100 wt. %, where wt. % refers to the ratio of the massof N or O to the total mass of N+O in the composition, excluding themetal of the metal oxynitride. As such, in reference to FIG. 4B, themetal oxynitride film 354 comprises greater than 0 wt. % nitrogen, andnot more than 100 wt. % nitrogen. The metal oxynitride film 354comprises greater than 0 wt. % oxygen, and not more than 15 wt. %oxygen; not more than 10 wt. % oxygen; not more than 5 wt. % oxygen.Non-limiting examples of useful atomic ratios of oxygen and nitrogen inthe metal oxynitride layer include, for example and without limitation:from 0.1% to 99.9% O with from 99.9% to 0.1% N; from 1% to 99% O withfrom 99% to 1% N; or from 10% to 90% O with from 90% to 10% N.

In one embodiment, the oxynitride is an oxynitride of the same metal asin the metal nitride layer 356 that contacts the metal oxynitride layer354. In another embodiment, the metal oxynitride layer 354 is a gradientlayer wherein the portion of the oxynitride layer that is closest to theuppermost dielectric layer 322 comprises a greater amount of oxygen, andthe opposite portion of the metal oxynitride layer 354, e.g., that isclosest to the metal nitride layer 356, comprises a greater amount ofnitrogen, for example, in atomic ratios described above. In oneembodiment, the metal oxynitride layer 354 and the metal nitride layer356 form a continuous, single gradient layer. In another embodiment, themetal oxynitride layer 354 is applied over a metal oxide layer and/or inbetween a metal oxide layer and a metal nitride layer. In anotherembodiment, the metal nitride layer 356 is not present, and the metaloxynitride film 354 is a gradient layer, wherein amount of oxygen in themetal oxynitride film decreases with increased distance from theuppermost dielectric layer. For example, the portion of the oxynitridelayer that is closest to the uppermost dielectric layer 322 comprises agreater amount of oxygen, and the opposite portion of the oxynitridelayer 354, comprises a greater amount of nitrogen, for example, inatomic ratios described above, for example and without limitation:ranging from 0.1% to 99.9% O with from 99.9% to 0.1% N; from 1% to 99% Owith from 99% to 1% N; or from 10% to 90% O with from 90% to 10% N.

In the protective coating 350 according to the present disclosure, themetal oxynitride film 354, such as a film comprised of siliconoxynitride, may have an index of refraction of at least 1.4, and notmore than 2.3. In one embodiment, the metal oxynitride film 354 has anindex of refraction of at least 1.45, and not more than 2.2. In anotherembodiment, the metal oxynitride film 354 has an index of refraction ofat least 1.75, and not more than 2.1. In yet another embodiment, themetal oxynitride film 354 has an index of refraction of at least 1.8,and not more than 2.1. It is to be understood that the index ofrefraction of the metal oxynitride film 354 at least partially dependson the weight percentage of nitrogen present in the metal oxynitridefilm 354. The protective coating 350 may be the uppermost layer of thecoated article.

The metal oxynitride film 354 can have a thickness in the range offrom >0 Å to 400 Å, such as from 70 Å to 400 Å, from 100 Å to 400 Å,from 280 Å to 330 Å, or from 110 Å to 130 Å. In embodiments where themetal oxynitride film 354 is a gradient layer, is the only film in theprotective coating, or where there is no metal nitride film in theprotective coating, it may have a thickness of 200 Å to 400 Å,preferably 225 Å to 375 Å, more preferably 250 Å to 350 Å, mostpreferably 280 Å to 330 Å.

The metal nitride film 356 can have a thickness in the range of from >0Å to 400 Å, such as from 70 Å to 400 Å, from 100 Å to 400 Å, from 250 Å400 Å, from 280 Å to 330 Å, from 200 Å to 250 Å, from 200 Å to 400 Å, orfrom 100 Å to 150 Å. In embodiments where there is no metal oxynitridelayer and/or no second protective film, the metal nitride film 356 canhave a thickness in the range of 100 Å to 400 Å, preferably 250 Å to 400Å, most preferably 280 Å to 330 Å. In embodiments where the protectivecoating has a metal oxynitride film 354 and a second protective layer,the metal nitride film 356 can have a thickness of 100 Å to 400 Å,preferably 150 Å to 330 Å, more preferably 175 Å to 300 Å, mostpreferably 200 Å to 250 Å. In embodiments where there protective coatinghas both a metal nitride 356 film and a second protective film 360, themetal oxynitride film can have a thickness of 50 Å to 200 Å, preferably75 Å to 175 Å, more preferably 100 Å to 150 Å, most preferably 110 Å to130 Å.

In certain embodiments, the invention has a combined thickness of themetal oxynitride film 354 (if present) and/or the metal nitride film 356(if present). That combined thickness can be between 200 Å and 800 Å,for example, 320 Å to 800 Å, 320 Å to 370 Å, or 280 Å to 330 Å.

The combined layer of metal nitride, metal oxynitride, metal nitride,and/or second protective film, such as TiAlO, can have a thicknessranging from >0 Å to 1000 Å, such as from 170 Å to 800 Å, from 320 Å to370 Å, from 280 Å to 330 Å, from 320 Å to 800 Å, from 310 Å to 360 Å,from 130 Å to 430 Å, from 320 Å to 800 Å, or from 350 Å to 400 Å.

With reference to FIGS. 3 and 4B, the metal oxynitride film 354 ofprotective coating 350 creates a stronger bond between the metal nitridefilm 356, and the metal oxide of the second film 326 of the uppermostdielectric layer 322 of the functional layer 320. Examples consistentwith this disclosure include a silicon nitride film 356 disposed overand in contact with at least part of a silicon oxynitride film 354,which is disposed over and in contact with at least part of a zincstannate uppermost dielectric layer 322.

It is to be understood that, in examples consistent with thisdisclosure, the silicon in the metal nitride film 356 and/or in themetal oxynitride film 354 may be replaced, at least in part, withoxides, oxynitrides, and nitrides, respectively, of other metals. Theseother metals may be the same or different between the films 354, 356.The metal may be titanium, hafnium, zirconium, niobium, zinc, bismuth,lead, indium, tin, aluminum, silicon and mixtures thereof.

With reference to FIGS. 4A and 4B, the coated article according to anyaspect or embodiment of the coated articles described herein, mayinclude a second protective film 360. The second protective film 360 isshown disposed over the metal nitride film 356, and may comprise, forexample, a metal oxide or metal nitride layer. The second protectivefilm 360 can be titania, alumina, silica, zirconia, tin oxide, a mixturethereof, or an alloy thereof. For example, the second protective film360 may include a mixture of silica and alumina; a mixture of titaniaand alumina; or zirconia. An example of the second film 360 may includeTiAlO. Non-limiting examples of the second protective film 360 may havea thickness range of such as 10 Å to 80 Å, such as 25 to 75 Å, such as35 Å to 55 Å. It is to be understood that the second protective film 360may be applied, e.g., as the top-most layer, to any other configurationof the uppermost dielectric layer, metal nitride, and metal oxynitridefilms consistent with the present disclosure. Alternatively, additionalfunctional layers or protective layers may be applied over the secondprotective film 360. Similarly, it is to be understood that a coatedarticle need not include a second protective film 360.

In non-limiting examples, the coated article may include an additionalprotective layer (not shown) positioned over the second protective film360. This additional protective layer can be any of the materials usedto form the protective coating 350, or the second protective film 360,or any material that may be used as a topcoat.

A primer, such as the optional primer 328 described above, may bepositioned over and/or in direct contact with any of the metallic layersof the functional layer 320, or any metallic layer that is a continuouslayer. In one non-limiting embodiment, the primer is not in directcontact with a discontinuous (subcritical) metal layer. In thisembodiment, a primer is not applied immediately over or in directcontact with the discontinuous layer. The primer layers, however, may bepositioned over and in direct contact with each of the continuousmetallic layers. Additionally, the primer may be titanium, or a mixtureor an alloy of titanium and aluminum, such as but not limited totitanium aluminide.

With reference to FIG. 5, a transparent article 400 may include asubstrate 410, a functional layer 420, and a protective coating 450.Although not shown, it is to be understood that some examples mayinclude a second protective film 360 (FIG. 4B) according to thisdisclosure as well, although a second protective film 360 may not beincluded as well. In the example depicted in FIG. 5, the protectivecoating 450 may comprise a second protective film consistent with thesecond protective film 360 disclosed above, or any other configurationor topcoat known in the art that is consistent with this disclosure. Thefunctional layer 420 may include a stack of metallic layers, dielectriclayers, and primer layers consistent with the present disclosure.

With further reference to FIG. 5, functional layer 420 includes anuppermost dielectric layer 422. The uppermost dielectric layer 422 maybe disposed at least partially over a primer layer 428, consistent withthe present disclosure. In non-limiting examples, the uppermostdielectric layer 422 consists of a single layer, and may have an indexof refraction of at least 1.5 and not more than 2.1, and more preferablyof at least 1.9, and not more than 1.9, and still more preferably of atleast 1.8, and not more than 1.85. In examples according to thisdisclosure, the uppermost dielectric layer 422 may consist of zincstannate. The features of the uppermost dielectric layer 422 may beconsistent with the features of the uppermost dielectric layer 322. Inother examples, the uppermost dielectric layer 322, 422 does notcomprise zinc 90 (90% zinc oxide, with 10% tin oxide).

It has been found through diligent testing that an uppermost dielectriclayer 322 including zinc stannate improves durability of the stack, andreduces corrosion/glitter defects, under such conditions. Additionally,use of an uppermost dielectric layer 322 consisting of zinc stannatedisposed on the upper most primer layer 328 of the functional layer 320does not impact color control. Alternatively, zinc oxide or zinc 90 maybe used at the uppermost dielectric layer. Alternatively, the uppermostdielectric layer can have two films, wherein the bottom film is a zincoxide film, and the top film is a zinc stannate film.

In reference to FIG. 6, coated article 500 comprises: a substrate 510,according to any embodiment or aspect described herein; a functionallayer 520 over the substrate 510; and a protective coating 550 over thefunctional layer 520. The functional layer 520 comprises a functionalstack 530, comprising a metal oxide layer 531, according to anyembodiment or aspect described herein, and a metallic layer 534,according to any embodiment or aspect described herein, over the metaloxide layer 531. An optional primer layer 528, according to anyembodiment or aspect described herein, is deposited over the metalliclayer 534. Functional layer 520 also comprises an uppermost dielectriclayer 522, according to any aspect or embodiment described herein.Protective coat 550 is a protective coating according to any aspect orembodiment described herein. In one embodiment, the substrate 510 isglass; the metal oxide layer 531 is a dielectric layer, such as a layerof zinc oxide 532 with a second layer of zinc stannate 533 over thelayer of zinc oxide; the metallic layer 534 comprises or consists of Ag;the primer layer 528 comprises or consists of Ti or TiAl; the dielectriclayer 522 comprises or consists of zinc oxide and/or zinc stannate; andthe protective coating 550 comprises a metal nitride layer comprisingone or more layers of SiON, SiON, or Si₃N₄ over the metal oxide layer522, and a second protective film 560 over the metal nitride layer 552.In one embodiment, e.g., in reference to FIG. 6, the metal nitride layer552 of the protective coating 550 comprises a layer of a siliconoxynitride 554 over, and in contact with, the metal oxide layer 522, anda layer of a silicon nitride 556 over, and in contact with, the siliconoxynitride layer 554.

Tables 1-6 provides examples of useful coated articles according to thepresent disclosure, including thicknesses, and preferred thicknesses ofthe various layers.

TABLE 1 SiN over zinc stannate Preferred Thickness range Thickness rangeMaterial (Å) (Å) Substrate Zn₂SnO₄ 250-400 270-330 ZnO  70-100 70-90 Ag 50-200 60-80 TiAl or Ti 10-30 10-30 Zn₂SnO₄  20-100 30-60 SiN 250-400280-330 TiAlO 250-400 270-330

TABLE 2 SiN over dielectric layer with zinc stannate layer over zincoxide layer Preferred Thickness range Thickness range Material (Å) (Å)Substrate Zn₂SnO₄ 250-400 270-330 ZnO  70-100 70-90 Ag  50-200 60-80TiAl or Ti 10-30 10-30 ZnO  20-100 30-60 Zn₂SnO₄  20-100 30-60 SiN100-400 280-330 TiAlO 250-400 270-330

TABLE 3 SiN over SiON over dielectric layer Preferred Thickness rangeThickness range Material (Å) (Å) Substrate Zn₂SnO₄ 250-400  270-330 ZnO(90%) 70-100 70-90 Ag 50-200 60-80 TiAl or Ti 10-30  10-30 Zn₂SnO₄20-100 30-60 SiON 70-400 110-130 SiN 150-400  200-250

TABLE 4 SiN over SiON over dielectric layer with TiAlO protective layerPreferred Thickness range Thickness range Material (Å) (Å) SubstrateZn₂SnO₄ 250-400 270-330 ZnO  70-100 70-90 Ag  50-200 60-80 TiAl or Ti10-30 10-30 Zn₂SnO₄  20-100 30-60 SiON  70-400 110-130 SiN 200-400200-250 TiAlO 100-400 270-330

TABLE 5 SiON over dielectric film with TiAlO protective layer PreferredThickness range Thickness range Material (Å) (Å) Substrate Zn₂SnO₄250-400  270-330 ZnO 70-100 70-90 Ag 50-200 60-80 TiAl or Ti 10-30 10-30 Zn₂SnO₄ 20-100 30-60 SiON 70-400 280-330 TiAlO 100-400  270-330

TABLE 6 SiON gradient film over dielectric film with TiAlO protectivelayer Preferred Thickness range Thickness range Material (Å) (Å)Substrate Zn₂SnO₄ 250-400 270-330 ZnO  70-100 70-90 Ag  50-200 60-80TiAl or Ti 10-30 10-30 Zn₂SnO₄  20-100 30-60 Gradient SiON (to SiN)100-400 280-330   (0%-100%)* (10% to 90%) TiAlO 100-400 270-330 *rangeof N % wt., excluding Si content, from Zn₂SnO₄ film to TiAlO film.

The following provides examples of coated articles according to thepresent disclosure. However, it is to be understood that the inventionis not limited to these specific embodiments.

EXAMPLES

Examples 1-6 are examples of coated articles according to the invention.While the example shows embodiments wherein the functional layerscomprises two dielectric layers and one metal layer, additionaldielectric and/or metal layers may be present according to theinvention. Furthermore, while the examples show embodiments wherein thetop-most layer is either the metal oxynitride film, metal nitride film,or second protective film, it is understood that additional functionalcoatings and/or additional protective layers may be applied over thetop-most layer shown in the examples. Furthermore, while the examplesshow the coating over a single piece of glass, it is understood thatthis coating may be applied to laminated glass, automotive glass,insulating glass units, etc.

Example 1

A substrate is coated with a functional layer. The substrate was glass.The functional layer includes a first dielectric layer disposed over thesubstrate, a metallic layer, a primer layer, and a second dielectriclayer. The first dielectric layer comprises a zinc stannate film and azinc oxide film. The metallic layer is disposed over the zinc oxide filmof the first dielectric layer. The metallic layer is a continuous silverlayer. A primer layer is disposed over the metallic layer, and a seconddielectric layer is disposed over the primer layer. The seconddielectric layer comprises zinc stannate. A protective layer is disposedover the second dielectric layer of the functional layer and comprisesSiN and a second protective layer disposed over the SiN layer,comprising TiAlO. All thicknesses are approximate.

Example 1 Material Thickness range (Å) Substrate Zn₂SnO₄ 250-400 ZnO 70-100 Ag 60-80 TiAl or Ti 10-30 Zn₂SnO₄ 30-60 SiN 280-330 TiAlO280-330

Example 2

A glass substrate is coated with a functional layer. The functionallayer includes a first dielectric layer, a metallic layer, a primerlayer, and a second dielectric layer. The first dielectric layer isdisposed over the substrate, and comprises a zinc stannate film and azinc oxide film positioned over the zinc stannate film. The metalliclayer is disposed over the first dielectric layer. The metallic layer isa continuous silver layer. The primer layer is disposed over themetallic layer. A second dielectric layer is disposed over the primerlayer. The second dielectric layer of this exemplary coated articlecomprises a first, zinc oxide film, and a second, zinc stannate filmthat is disposed over the first layer. A protective coating is disposedover the functional layer, and is in contact with the zinc stannate filmof the second dielectric layer. The first protective layer comprisesSiN. A second protective layer is disposed over the first protectivelayer, and comprises TiAlO. All thicknesses are approximate.

Example 2 Material Thickness range (Å) Glass Zn₂SnO₄ 250-400 ZnO  70-100Ag 60-80 TiAl or Ti 10-30 ZnO  70-100 Zn₂SnO₄ 30-60 SiN 100-400 TiAlO280-330

Example 3

A substrate is coated with a functional layer. The substrate may be ofany suitable material, such as glass. The functional layer includes afirst dielectric layer disposed over the substrate, a metallic layer, aprimer layer, and a second dielectric layer. The first dielectric layercomprises a zinc stannate film and a zinc oxide film. The metallic layeris disposed over the zinc oxide film of the first dielectric layer. Themetallic layer is a continuous silver layer. A primer layer is disposedover the metallic layer, and a second dielectric layer is disposed overthe primer layer. The second dielectric layer consists of zinc stannate.A protective coating is disposed over the second dielectric layer of thefunctional layer and comprises a SiN layer, and an SiON layer disposedbetween the SiN layer and the dielectric layer. All thicknesses areapproximate.

Example 3 Material Thickness range (Å) Substrate Zn₂SnO₄ 250-400 ZnO 70-100 Ag 60-80 TiAl or Ti 10-30 Zn₂SnO₄ 30-60 SiON  70-400 SiN 250-400

Example 4

A glass substrate is coated with a functional layer. The functionallayer includes a first dielectric layer, a metallic layer, a primerlayer, and a second dielectric layer that is an uppermost layer of thefunctional layer. The first dielectric layer is disposed over thesubstrate, and comprises a zinc stannate film and a zinc oxide filmpositioned over the zinc stannate film. The metallic layer is disposedover the first dielectric layer. The metallic layer is a continuoussilver layer. The primer layer is disposed over the metallic layer. Asecond dielectric layer is disposed over the primer layer. The seconddielectric layer of this exemplary coated article consists of a zincstannate film. A protective coating is disposed over the functionallayer, and is in contact with the zinc stannate second dielectric layer.The protective coating is disposed over the second dielectric layer ofthe functional layer and comprises a SiN layer, and an SiON layerdisposed between the SiN layer and the dielectric layer. All thicknessesare approximate. A second protective layer is disposed over the SiNlayer, and comprises TiAlO. All thicknesses are approximate.

Example 4 Material Thickness range (Å) Glass Zn₂SnO₄ 250-400 ZnO  70-100Ag 60-80 TiAl or Ti 10-30 Zn₂SnO₄ 30-60 SiON 120 SiN 200-250 TiAlO280-330

Example 5

A glass substrate is coated with a functional layer. The functionallayer includes a first dielectric layer, a metallic layer, a primerlayer, and a second dielectric layer. The first dielectric layer isdisposed over the substrate, and comprises a zinc stannate film and azinc oxide film positioned over the zinc stannate film. The metalliclayer is disposed over the first dielectric layer. The metallic layer isa continuous silver layer. The primer layer is disposed over themetallic layer. A second dielectric layer is disposed over the primerlayer. The second dielectric layer of this exemplary coated articlecomprises a zinc stannate film. A protective coating is disposed overthe functional layer, and is in contact with the zinc stannate film ofthe second dielectric layer. The first protective layer comprises SiON.A second protective layer is disposed over the first protective layer,and comprises TiAlO. All thicknesses are approximate.

Example 5 Material Thickness range (Å) Glass Zn₂SnO₄ 250-400 ZnO  70-100Ag 60-80 TiAl or Ti 10-30 Zn₂SnO₄ 30-60 SiON 280-330 TiAlO 280-330

Example 6

A glass substrate is coated with a functional layer. The functionallayer includes a first dielectric layer, a metallic layer, a primerlayer, and a second dielectric layer. The first dielectric layer isdisposed over the substrate, and comprises a zinc stannate film and azinc oxide film positioned over the zinc stannate film. The metalliclayer is disposed over the first dielectric layer. The metallic layer isa continuous silver layer. The primer layer is disposed over themetallic layer. A second dielectric layer is disposed over the primerlayer. The second dielectric layer of this exemplary coated articlecomprises a zinc stannate film. A protective coating is disposed overthe functional layer, and is in contact with the zinc stannate film ofthe second dielectric layer. The first protective layer comprises SiONin a gradient film, with N content increasing, and O content decreasingin a direction from the zinc stannate film to the second protectivelayer, which is disposed over the first protective layer, and comprisesTiAlO. All thicknesses are approximate.

Example 6 Material Thickness range (Å) Glass Zn₂SnO₄ 250-400 ZnO  70-100Ag 60-80 TiAl or Ti 10-30 Zn₂SnO₄ 30-60 SiON gradient 280-330 TiAlO280-330

The following numbered clauses are illustrative of various aspects ofthe invention:

Clause 1. A coated article comprising a substrate, a first functionallayer over at least a portion of the substrate, and a protective coatingover at least a portion of the functional layer, wherein an uppermostlayer of the functional layer is a metal oxide film, and wherein theprotective coating comprises one or more layers of a metal nitride, ametal oxynitride, or a combination thereof.

Clause 2. The coated article of clause 1, wherein the metal nitride, themetal oxynitride, or the combination thereof is at least one of siliconnitride, silicon oxynitride, or a combination thereof.

Clause 3. The coated article of clause 1, wherein the protective coatingcomprises a metal oxynitride film over and in contact with at least partof the metal oxide film of the uppermost layer of the first functionallayer; and a metal nitride film over and in contact with at least a partof the metal oxynitride film.

Clause 4. The coated article of any one of clauses 1-3, wherein theprotective coating comprises a silicon nitride film.

Clause 5. The coated article of any one of clauses 1-3, wherein theprotective coating comprises a silicon oxynitride film.

Clause 6. The coated article of clause 3, wherein the metal oxynitridefilm is a gradient layer in which the portion of the metal oxynitridefilm closest to the uppermost layer of the first functional layercomprises a greater amount of oxygen than the portion of the metaloxynitride film closest to the metal nitride film.

Clause 7. The coated article of clause 1, wherein the protective coatingcomprises a metal oxynitride film over and in contact with at leastportion of the metal oxide film of the uppermost layer of the firstfunctional layer, wherein the metal oxynitride film is a gradient layerin which the amount of oxygen in the metal oxynitride film decreaseswith increased distance from the uppermost layer of the first functionallayer or in which a portion of the metal oxynitride film closest to theuppermost layer of the first functional layer comprises a greater amountof oxygen than a portion of the metal oxynitride film farthest from theuppermost layer of the first functional layer.

Clause 8. The coated article of clause 7, wherein the metal oxynitrideof the gradient layer is silicon oxynitride.

Clause 9. The coated article of any one of clauses 1-8, wherein themetal oxide film of the uppermost dielectric layer of the firstfunctional layer comprises a zinc stannate or zinc oxide and the metaloxide film is immediately below and in contact with the protectivecoating.

Clause 10. The coated article of any one of clauses 1-9, wherein thefirst functional layer comprises a dielectric layer over at least aportion of the substrate, a metallic layer over at least a portion ofthe dielectric layer, and the uppermost layer over at least a portion ofthe metallic layer.

Clause 11. The coated article of clause 10, wherein the first functionallayer further comprises a primer layer over the metallic layer and underat least a portion of the uppermost layer.

Clause 12. The coated article of clause 10 or 11, wherein the dielectriclayer comprises one or more layers comprising zinc oxide and/or zincstannate, the metallic layer comprises Ag, Cu, Au and/or Pd, and/or theuppermost layer comprises zinc oxide and/or zinc stannate.

Clause 13. The coated article of clause 12, wherein the uppermost layerof the functional layer does not comprise zinc oxide.

Clause 14. The coated article of any one of clauses 1-13, furthercomprising a second functional layer beneath at least a portion of thefirst functional layer and over at least a portion of the substrate.

Clause 15. The coated article of clause 14, wherein the secondfunctional layer comprises a second dielectric layer, a second metalliclayer over the second dielectric layer, and, optionally, a second primerlayer over the metallic layer.

Clause 16. The coated article of any one of clauses 1-15, furthercomprising a second protective film disposed at least partially over theone or more layers of a metal nitride, a metal oxynitride, or acombination thereof, and wherein the second protective film comprises atleast one of titania, alumina, silica, zirconia, a mixture of any two ormore of the preceding, or an alloy of any one or more of the preceding.

Clause 17. The coated article of clause 16, wherein the secondprotective film comprises TiO₂ and/or TiAlO.

Clause 18. The coated article of any one of clauses 1-17, wherein thefunctional layer comprises a metallic layer and a primer layer over atleast a portion of the metallic layer.

Clause 19. The coated article of clause 18, wherein the primer layercomprises titanium, or titanium and aluminum, and wherein at least aportion of the titanium, or titanium and aluminum are optionallyoxidized after the titanium or titanium and aluminum are deposited overthe metallic layer.

Clause 20. The coated article of clause 18, wherein the metallic layercomprises silver, gold, palladium, copper, or a mixture of any of thepreceding.

Clause 21. The coated article of any one of clauses 18-20, wherein themetallic layer is a continuous metallic film.

Clause 22. The coated article of any one of clauses 18-21, wherein themetallic layer comprises silver, copper, or a mixture thereof.

Clause 23. The coated article of clause 1, comprising: a glasssubstrate; a first layer of zinc stannate over at least a portion of theglass substrate; a layer of zinc oxide over at least a portion of thelayer of zinc stannate; a layer of silver over at least a portion of thelayer of zinc oxide; a primer layer comprising Ti, TiAl and/or oxidesthereof over at least a portion of the layer of silver; a second layerof zinc stannate or zinc oxide over at least a portion of the primerlayer; a metal oxynitride layer comprising silicon oxynitride directlyover at least a portion of the second layer of zinc stannate; a metalnitride layer comprising silicon directly over at least a portion of themetal oxynitride layer; and a second protective layer comprising Ti,TiAl, and/or oxides of either of the preceding over at least a portionof the metal nitride layer.

Clause 24. The coated article of clause 1, comprising: a glasssubstrate; a first layer of zinc stannate directly over at least aportion of the glass substrate; a layer of zinc oxide directly over atleast a portion of the layer of zinc stannate; a layer of silverdirectly over at least a portion of the layer of zinc oxide; a primerlayer comprising Ti, TiAl, and/or oxides of either of the precedingdirectly over at least a portion of the layer of silver; a second layerof zinc stannate directly over at least a portion of the primer layer; ametal oxynitride layer comprising silicon directly over at least aportion of the second layer of zinc stannate; a metal nitride layercomprising silicon directly over at least a portion of the metaloxynitride layer; and a second protective layer comprising TiAlOdirectly over at least a portion of the metal nitride layer.

Clause 25. The coated article of clause 1, comprising: a glasssubstrate; a first layer of zinc stannate over at least a portion of theglass substrate and having a thickness ranging from 250 Å to 400 Å; alayer of zinc oxide over at least a portion of the layer of zincstannate and having a thickness ranging from 70 Å to 90 Å; a layer ofsilver over at least a portion of the layer of zinc oxide and having athickness ranging from 70 Å to 90 Å; a primer layer comprising Ti overat least a portion of the layer of silver and having a thickness rangingfrom 10 Å to 30 Å; a second layer of zinc stannate over at least aportion of the primer layer and having a thickness ranging from 30 Å to100 Å; a metal oxynitride layer comprising SiON directly over at least aportion of the second layer of zinc stannate and having a thicknessranging from 70 Å to 400 Å; a metal nitride layer comprising SiNdirectly over at least a portion of the metal oxynitride layer andhaving a thickness ranging from 100 Å to 400 Å; and a second protectivelayer comprising TiAlO over the metal nitride layer and having athickness ranging from 100 Å to 400 Å.

Clause 26. The coated article of any one of clauses 1-25 mounted in abody of a vehicle.

Clause 27. The coated article of clause 26, mounted in an automobile asa sunroof.

Clause 28. The coated article of any one of clauses 1-25, mounted in aninsulating glass unit.

Clause 29. A coated article comprising a substrate, a functional layer,having an uppermost layer, over at least a portion of the substrate, anda protective coating over at least a portion of the functional layer,wherein the uppermost layer of the functional layer is a dielectriclayer having an index of refraction of at least 1.5, and not more than2.1.

Clause 30. The coated article of clause 29, wherein the uppermost layerof the functional layer consists of zinc stannate.

Clause 31. The coated article of clause 29, wherein the uppermost layerof the functional layer does not include zinc oxide.

Clause 32. A coated article comprising a substrate, a functional layerover at least a portion of the substrate, and a protective coating overat least a portion of the functional layer, wherein the functional layercomprises at least one metallic layer and a primer layer disposed atleast partially over and in contact with at least part of the at leastone metallic layer, and wherein an uppermost layer of the functionallayer is disposed over and in contact with at least part of the primerlayer, and the uppermost layer of the functional layer does not includezinc oxide.

Clause 33. An insulating glass unit comprising a first ply having anumber 1 surface and a number 2 surface, a second ply having a number 3surface and a number 4 surface, and a coating comprising the functionallayer and the protective coating as described in any of the clauses1-31, wherein the coating is positioned over at least a portion of thenumber 2 surface or the number 3 surface.

Clause 34. The insulating glass unit according to clause 33 wherein thecoating is positioned over the number 2 surface.

Clause 35. The insulating glass unit according to clause 33 or 34further comprising a space between the number 2 surface of the first plyand the number 3 surface of the second ply, wherein the space is filledwith a gas.

Clause 36. The insulating glass unit according to clause 35 wherein thegas is argon.

Clause 37. An automotive glass article comprising a first ply having anumber 1 surface and a number 2 surface, and a coating comprising thefunctional layer and the protective coating as described in any of theclauses 1-31, wherein the coating is positioned over at least a portionof the number 1 surface or number 2 surface.

Clause 38. The automotive glass article according to clause 34 whereinthe coating is positioned over the number 2 surface.

It will be readily appreciated by those skilled in the art thatmodifications may be made to the invention without departing from theconcepts disclosed in the foregoing description. Accordingly, theparticular embodiments described in detail herein are illustrative onlyand are not limiting to the scope of the invention, which is to be giventhe full breadth of the appended claims and any and all equivalentsthereof.

What is claimed is:
 1. A coated article comprising: a substrate; a firstfunctional layer over at least a portion of the substrate, the firstfunctional layer comprising a silver layer over at least a portion ofthe substrate and an uppermost layer comprising a metal oxide over atleast a portion of the silver layer; a metal oxynitride layer comprisingsilicon directly over at least a portion of the uppermost layercomprising a metal oxide; a metal nitride layer comprising silicon overat least a portion of the metal oxynitride layer; and a protective layercomprising TiAlO over at least a portion of the metal nitride layer. 2.The coated article of claim 1, wherein the metal oxynitride layercomprising silicon is a gradient layer in which the portion of the metaloxynitride layer closest to the uppermost layer of the first functionallayer comprises a greater amount of oxygen than the portion of the metaloxynitride layer closest to the metal nitride layer.
 3. The coatedarticle of claim 1, wherein the uppermost layer of the first functionallayer comprises zinc stannate.
 4. The coated article of claim 1, whereinthe first functional layer comprises a dielectric layer over at least aportion of the substrate and the silver layer over at least a portion ofthe dielectric layer.
 5. The coated article of claim 4, wherein thefirst functional layer further comprises a primer layer over at least aportion of the silver layer and under at least a portion of theuppermost layer.
 6. The coated article of claim 5, wherein the primerlayer comprises titanium, or titanium and aluminum.
 7. The coatedarticle of claim 6, wherein at least a portion of the titanium, ortitanium and aluminum are oxidized after the titanium or titanium andaluminum are deposited over the silver layer.
 8. The coated article ofclaim 5, wherein the dielectric layer comprises one or more layerscomprising zinc oxide and/or zinc stannate and/or the uppermost layercomprises zinc oxide and/or zinc stannate.
 9. The coated article ofclaim 1, wherein the uppermost layer of the functional layer does notcomprise zinc oxide.
 10. The coated article of claim 1, furthercomprising a second functional layer beneath at least a portion of thefirst functional layer and over at least a portion of the substrate. 11.The coated article of claim 1, wherein the metal nitride layer isdirectly over the metal oxynitride layer.
 12. The coated article ofclaim 1, mounted in a body of a vehicle or an insulating glass unit. 13.A coated article, comprising: a glass substrate; a first layer of zincstannate directly over at least a portion of the glass substrate; alayer of zinc oxide directly over at least a portion of the layer ofzinc stannate; a layer of silver directly over at least a portion of thelayer of zinc oxide; a primer layer comprising Ti, TiAl, and/or oxidesof either of the preceding directly over at least a portion of the layerof silver; a second layer of zinc stannate directly over at least aportion of the primer layer; a metal oxynitride layer comprising silicondirectly over at least a portion of the second layer of zinc stannate; ametal nitride layer comprising silicon directly over at least a portionof the metal oxynitride layer; and a protective layer comprising TiAlOdirectly over at least a portion of the metal nitride layer.
 14. Acoated article, comprising: a glass substrate; a first layer of zincstannate over at least a portion of the glass substrate and having athickness ranging from 250 Å to 400 Å; a layer of zinc oxide over atleast a portion of the layer of zinc stannate and having a thicknessranging from 70 Å to 90 Å; a layer of silver over at least a portion ofthe layer of zinc oxide and having a thickness ranging from 70 Å to 90Å; a primer layer comprising Ti over at least a portion of the layer ofsilver and having a thickness ranging from 10 Å to 30 Å; a second layerof zinc stannate over at least a portion of the primer layer and havinga thickness ranging from 30 Å to 100 Å; a metal oxynitride layercomprising SiON directly over at least a portion of the second layer ofzinc stannate and having a thickness ranging from 70 Å to 400 Å; a metalnitride layer comprising SiN directly over at least a portion of themetal oxynitride layer and having a thickness ranging from 100 Å to 400Å; and a protective layer comprising TiAlO over the metal nitride layerand having a thickness ranging from 100 Å to 400 Å.